Matsumoto Yoriaki, Higaki Toru, Arataki Keiko, Masuda Takanori, Sato Tomoyasu, Fukumoto Wataru, Nakamura Yuko, Tatsugami Fuminari, Awai Kazuo
Department of Diagnostic Radiology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Minami-ku.
Department of Gastroenterology, Tsuchiya General Hospital.
J Comput Assist Tomogr. 2020 Mar/Apr;44(2):230-235. doi: 10.1097/RCT.0000000000001000.
We developed a patient-specific contrast enhancement optimizer (p-COP) that can exploratorily calculate the contrast injection protocol required to obtain optimal enhancement at target organs using a computer simulator. Appropriate contrast media dose calculated by the p-COP may minimize interpatient enhancement variability. Our study sought to investigate the clinical utility of p-COP in hepatic dynamic computed tomography (CT).
One hundred thirty patients (74 men, 56 women; median age, 65 years) undergoing hepatic dynamic CT were randomly assigned to 1 of 2 contrast media injection protocols using a random number table. Group A (n = 65) was injected with a p-COP-determined iodine dose (developed by Higaki and Awai, Hiroshima University, Japan). In group B (n = 65), a standard protocol was used. The variability of measured CT number (SD) between the 2 groups of aortic and hepatic enhancement was compared using the F test. In the equivalence test, the equivalence margins for aortic and hepatic enhancement were set at 50 and 10 Hounsfield units (HU), respectively. The rate of patients with an acceptable aortic enhancement (250-350 HU) for the diagnosis of hypervascular liver tumors was compared using the χ test.
The mean ± SD values of aortic and hepatic enhancement were 311.0 ± 39.9 versus 318.7 ± 56.5 and 59.0 ± 11.5 versus 58.6 ± 11.8 HU in groups A and B, respectively. Although the SD for aortic enhancement was significantly lower in group A (P = 0.006), the SD for hepatic enhancement was not significantly different (P = 0.871). The 95% confidence interval for the difference in aortic and hepatic enhancement between the 2 groups was within the range of the equivalence margins. The number of patients with acceptable aortic enhancement was significantly greater in group A than in group B (P < 0.01).
The p-COP software reduced interpatient variability in aortic enhancement and obtained acceptable aortic enhancement at a significantly higher rate compared with the standard injection protocol for hepatic dynamic CT.
我们开发了一种针对患者的对比剂增强优化器（p-COP），它可以使用计算机模拟器探索性地计算在目标器官获得最佳增强效果所需的对比剂注射方案。由p-COP计算出的合适对比剂剂量可能会使患者间的增强差异最小化。我们的研究旨在探讨p-COP在肝脏动态计算机断层扫描（CT）中的临床应用价值。
130例接受肝脏动态CT检查的患者（74例男性，56例女性；中位年龄65岁）使用随机数字表随机分为两种对比剂注射方案中的一组。A组（n = 65）注射由日本广岛大学的Higaki和Awai开发的p-COP确定的碘剂量。B组（n = 65）采用标准方案。使用F检验比较两组主动脉和肝脏增强时测量的CT值（标准差）的变异性。在等效性检验中，主动脉和肝脏增强的等效界值分别设定为50和10亨氏单位（HU）。使用χ检验比较主动脉增强可接受（250 - 350 HU）用于诊断富血供肝肿瘤的患者比例。
A组和B组主动脉和肝脏增强的均值±标准差分别为311.0±39.9与318.7±56.5以及59.0±11.5与58.6±11.8 HU。虽然A组主动脉增强的标准差显著更低（P = 0.006），但肝脏增强的标准差无显著差异（P = 0.871）。两组间主动脉和肝脏增强差异的95%置信区间在等效界值范围内。A组主动脉增强可接受的患者数量显著多于B组（P < 0.01）。
与肝脏动态CT的标准注射方案相比，p-COP软件降低了患者间主动脉增强的变异性，并以显著更高的比例获得了可接受的主动脉增强效果。
